On Sat, 4 Feb 2023 at 09:36, Ira Weiny ira.weiny@intel.com wrote:
The kernel pages used by shm_get_kernel_pages() are allocated using GFP_KERNEL through the following call stack:
trusted_instantiate() trusted_payload_alloc() -> GFP_KERNEL <trusted key op> tee_shm_register_kernel_buf() register_shm_helper() shm_get_kernel_pages()
Where <trusted key op> is one of:
trusted_key_unseal() trusted_key_get_random() trusted_key_seal()Because the pages can't be from highmem get_kernel_pages() boils down to a get_page() call.
Remove the get_kernel_pages() call and open code the get_page().
In case a highmem page does slip through warn on once for a kmap'ed address.
Cc: Jens Wiklander jens.wiklander@linaro.org Cc: Al Viro viro@zeniv.linux.org.uk Cc: "Fabio M. De Francesco" fmdefrancesco@gmail.com Cc: Christoph Hellwig hch@lst.de Cc: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Ira Weiny ira.weiny@intel.com
Changes from v1: Al/Christoph: Remove kiov altogether
drivers/tee/tee_shm.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-)
Reviewed-by: Sumit Garg sumit.garg@linaro.org
-Sumit
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index 527a6eabc03e..b1c6231defad 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -11,6 +11,7 @@ #include <linux/tee_drv.h> #include <linux/uaccess.h> #include <linux/uio.h> +#include <linux/highmem.h> #include "tee_private.h"
static void shm_put_kernel_pages(struct page **pages, size_t page_count) @@ -24,26 +25,20 @@ static void shm_put_kernel_pages(struct page **pages, size_t page_count) static int shm_get_kernel_pages(unsigned long start, size_t page_count, struct page **pages) {
struct kvec *kiov;
struct page *page; size_t n;
int rc;if (WARN_ON_ONCE(is_vmalloc_addr((void *)start)))
if (WARN_ON_ONCE(is_vmalloc_addr((void *)start) ||is_kmap_addr((void *)start))) return -EINVAL;
kiov = kcalloc(page_count, sizeof(*kiov), GFP_KERNEL);if (!kiov)return -ENOMEM;
page = virt_to_page(start); for (n = 0; n < page_count; n++) {
kiov[n].iov_base = (void *)(start + n * PAGE_SIZE);kiov[n].iov_len = PAGE_SIZE;
pages[n] = page + n;get_page(pages[n]); }
rc = get_kernel_pages(kiov, page_count, 0, pages);kfree(kiov);return rc;
return page_count;}
static void release_registered_pages(struct tee_shm *shm)
-- 2.39.1